1. Field of the Invention
The present invention relates generally to the winding of a filament onto a bobbin or canister, and, more particularly, to a method and apparatus for controlling the winding of a filament onto a bobbin or canister with great consistency.
2. Description of Related Art
There are many requirements for a filament to be wound onto a bobbin or canister in uniform winding layers where any inconsistencies, such as climb back or gapping, make the final winding unacceptable. Exemplary of one such use is where a wound optical fiber or metal wire filament is dispensed during flight of a vehicle to maintain a data link with launch site equipment. In such use, an incorrectly or inaccurately wound bobbin may induce stress in the filament during dispense that can cause it to break or be stressed to the point that transmission efficiency of data is substantially reduced. Moreover, in the case of an optical fiber whose dimensions may be in the order of thousandths of an inch, the winding of a bobbin is a relatively difficult proposition in that because of the fiber small cross-sectional dimensions inconsistencies can readily occur.
All known so-called automatic filament winding machines have relatively awkward techniques for transition forming (i.e.) moving from one layer to the next layer) and cross-over control. Some of the known automatic winding equipment contemplates program speed reduction at the end of each layer to alleviate the transition process which is quite costly in labor as well as resulting in production time loss and need for floor space for the extra equipment required.
There are other known systems that operate on a vision principle in which a light beam, such as a laser, tracks the winding filament and on detecting variations from norm shuts down the winding operation to enable correcting inconsistencies. Such a system is disclosed in copending U.S. patent application Ser. No. 07/669,251, BOBBIN WINDING CONTROL by B. F. Berlin et al. filed Mar. 14, 1991 and assigned to the same assignee as the present application. This vision system offers prospects of being highly effective in use even though it utilizes relatively expensive equipment, the cost of which may be prohibitive under certain circumstances.
U.S. Pat. No. 3,604,647, MACHINE FOR WINDING BOBBINS by George W. LeCompte et al. and assigned to the same assignee as the present application discloses wire winding apparatus having a freely oscillating arm mounted on a reversing plate. The wire on leaving a pulley located on the outer end of the arm is wound onto a bobbin with the arm freely pivoting to follow the winding as it is formed on a layer. Solenoids alternately move the reversing plate to each of two limits as a layer is finished.